PyPy cPickle crash with Mercurial

   $ hg histedit --continue
-  saved backup bundle to $TESTTMP/foo/.hg/strip-backup/08d98a8350f3-02594089-backup.hg (glob)
+  ** unknown exception encountered, please report by visiting
+  ** https://mercurial-scm.org/wiki/BugTracker
+  ** Python 2.7.10 (5f8302b8bf9f, Nov 18 2015, 10:38:03)[PyPy 4.0.1 with GCC 4.2.1 Compatible Apple LLVM 5.1 (clang-503.0.40)]
+  ** Mercurial Distributed SCM (version 3.6.2+628-8c45e1eed739)
+  ** Extensions loaded: histedit
+  Traceback (most recent call last):
+    File "bin/hg", line 43, in <module>
+      mercurial.dispatch.run()
+    File "mercurial/dispatch.py", line 54, in run
+      sys.exit((dispatch(request(sys.argv[1:])) or 0) & 255)
+    File "mercurial/dispatch.py", line 116, in dispatch
+      ret = _runcatch(req)
+    File "mercurial/dispatch.py", line 187, in _runcatch
+      return _dispatch(req)
+    File "mercurial/dispatch.py", line 910, in _dispatch
+      cmdpats, cmdoptions)
+    File "mercurial/dispatch.py", line 669, in runcommand
+      ret = _runcommand(ui, options, cmd, d)
+    File "mercurial/dispatch.py", line 1041, in _runcommand
+      return checkargs()
+    File "mercurial/dispatch.py", line 1001, in checkargs
+      return cmdfunc()
+    File "mercurial/dispatch.py", line 907, in <lambda>
+      d = lambda: util.checksignature(func)(ui, *args, **cmdoptions)
+    File "mercurial/util.py", line 985, in check
+      return func(*args, **kwargs)
+    File "hgext/histedit.py", line 892, in histedit
+      _histedit(ui, repo, state, *freeargs, **opts)
+    File "hgext/histedit.py", line 960, in _histedit
+      state.read()
+    File "hgext/histedit.py", line 262, in read
+      data = pickle.load(fp)
+    File "pypy-4.0.1-osx64/lib_pypy/cPickle.py", line 596, in load
+      return Unpickler(f).load()
+    File "pypy-4.0.1-osx64/lib_pypy/cPickle.py", line 170, in load
+      self.dispatch[key](self)
+  KeyError: 118